<html>
<head>
	<meta charset="UTF-8">
	<meta content="IE=edge" http-equiv="X-UA-Compatible">
	<meta content="initial-scale=1.0, maximum-scale=1.0, user-scalable=no, width=device-width" name="viewport">
	<title>3477：[Usaco2014 Mar]Sabotage</title>
	<!-- css -->
	<link href="../css/base.min.css" rel="stylesheet">
	<link href="../css/project.min.css" rel="stylesheet">
	
	<!-- favicon -->
	<!-- ... -->
</head>
<body class="page-brand">
	<header class="header header-transparent header-waterfall ui-header">
		<ul class="nav nav-list pull-left">
			<li>
				<a data-toggle="menu" href="#menu">
					<span class="icon icon-lg">menu</span>
				</a>
			</li>
		</ul>
		<a class="header-logo header-affix-hide margin-left-no margin-right-no" data-offset-top="213" data-spy="affix">[Usaco2014 Mar]Sabotage</a>
		<span class="header-logo header-affix margin-left-no margin-right-no" data-offset-top="213" data-spy="affix">[Usaco2014 Mar]Sabotage</span>
	</header>
	<nav aria-hidden="true" class="menu" id="menu" tabindex="-1">
		<div class="menu-scroll">
			<div class="menu-content">
				<a class="menu-logo" href="../index.html">BZOJ离线题库</a>
				<ul class="nav">
					<li>
						<a class="waves-attach" data-toggle="collapse" href="#problems">题目</a>
						<ul class="menu-collapse collapse in" id="problems">
							<li>
								<a class="waves-attach" href="../index.html">主页</a>
							</li>
							<li>
								<a class="waves-attach" href="../list.html">题目列表</a>
							</li>
						</ul>
					</li>
					<li>
						<a class="collapsed waves-attach" data-toggle="collapse" href="#about">关于</a>
						<ul class="menu-collapse collapse" id="about">
							<li>
								<a class="waves-attach" href="../about.html">关于此项目</a>
							</li>
						</ul>
					</li>
					
				</ul>
			</div>
		</div>
	</nav>
	<main class="content">
		<div class="content-header ui-content-header">
			<div class="container">
				<h1 class="content-heading">
                [Usaco2014 Mar]Sabotage                </h1>
                <p>时间限制：10s&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;  空间限制：128MB</p>			</div>
		</div>
		<div class="container">
			<section class="content-inner margin-top-no">
				<div class="row">
					<div class="col-lg-13 col-md-13">
						<div class="card margin-bottom-no">
							<div class="card-main">
								<div class="card-inner">
									
                                <h3>题目描述</h3><p><p><span style="font-size: medium">Farmer John's arch-nemesis, Farmer Paul, has decided to sabotage Farmer John's milking equipment! The milking equipment consists of a row of N (3 &lt;= N &lt;= 100,000) milking machines, where the ith machine produces M_i units of milk (1 &lt;= M_i &lt;= 10,000). Farmer Paul plans to disconnect a contiguous block of these machines -- from the ith machine up to the jth machine (2 &lt;= i &lt;= j &lt;= N-1); note that Farmer Paul does not want to disconnect either the first or the last machine, since this will make his plot too easy to discover. Farmer Paul's goal is to minimize the average milk production of the remaining machines. Farmer Paul plans to remove at least 1 cow, even if it would be better for him to avoid sabotage entirely. Fortunately, Farmer John has learned of Farmer Paul's evil plot, and he is wondering how bad his milk production will suffer if the plot succeeds. Please help Farmer John figure out the minimum average milk production of the remaining machines if Farmer Paul does succeed. </span></p>
<p>约翰的牧场里有 N 台机器，第 i 台机器的工作能力为 Ai。保罗阴谋破坏一些机器，使得约翰的<br />
工作效率变低。保罗可以任意选取一段编号连续的机器，使它们停止工作。但这样的破坏只能搞一次，<br />
而且保罗无法破坏第一台或最后一台机器。请问他该破坏哪些机器才能让剩下机器的工作效率的平均<br />
数最小？为了显示存在感，保罗至少必须破坏一台机器。</p></p><hr/><h3>输入格式</h3><p><p><font size="4">* Line 1: The integer N. </font></p>
<p><font size="4">* Lines 2..1+N: Line i+1 contains M_i.</font></p>
<p><font size="4">&nbsp;</font></p></p><hr/><h3>输出格式</h3><p><p><font size="4">* Line 1: The lowest possible average Farmer Paul can achieve, rounded to 3 digits after the decimal point, and printed with 3 digits after the decimal point. </font></p></p><hr/><h3>样例输入</h3><pre>5 
5 
1 
7 
8 
2

 </pre><hr/><h3>样例输出</h3><pre>2.667 
OUTPUT DETAILS: The optimal solution is to remove the 7 and 8, leaving 5, 1, and 2, whose average is 8/3. </pre><hr/><h3>提示</h3><p>没有写明提示</p><hr/><h3>题目来源</h3><p>Gold</p>
								</div>
							</div>
						</div>
					</div>
				</div>
				
				
			</section>
		</div>
	</main>

	<div class="fbtn-container">
		<div class="fbtn-inner">
			<a class="fbtn fbtn-lg fbtn-brand-accent waves-attach waves-circle waves-light waves-effect" data-toggle="dropdown" aria-expanded="true"><span class="fbtn-text fbtn-text-left">Menu</span><span class="fbtn-ori icon">apps</span><span class="fbtn-sub icon">close</span></a>
			<div class="fbtn-dropup">
				<a class="fbtn fbtn-brand waves-attach waves-circle waves-light waves-effect" href="../list.html" target="_self"><span class="fbtn-text fbtn-text-left">题目列表</span><span class="icon">menu</span></a>
				<a class="fbtn fbtn-green waves-attach waves-circle waves-effect" href="../index.html" target="_self"><span class="fbtn-text fbtn-text-left">返回主页</span><span class="icon">home</span></a>
				<a class="fbtn waves-attach waves-circle waves-effect" href="http://www.lydsy.com/JudgeOnline/submitpage.php?id=3477" target="_blank"><span class="fbtn-text fbtn-text-left">提交代码</span><span class="icon">send</span></a>
				<a class="fbtn fbtn-orange waves-attach waves-circle waves-effect" href="http://www.lydsy.com/JudgeOnline/wttl/wttl.php?pid=3477" target="_blank"><span class="fbtn-text fbtn-text-left">试题讨论</span><span class="icon">chat</span></a>
				
			</div>
		</div>
	</div>

	<!-- js -->
	<script src="../js/jquery.min.js"></script>
	<script src="../js/base.min.js"></script>
	<script src="../js/project.min.js"></script>
</body>
</html>